Lateral Approach to the Knee

Position

• supine
• sandbag under buttock
• flex knee to 90°
• foot rest
• lateral support

Landmarks

• Lateral border of patella
• Lateral joint line
• Gerdy’s tubercle
  • Inferior attachment of iliotibial band

Incision

• Curved longitudinal incision
• Start: Level of the middle of the patella & 3 cm lateral to it
• Over Gerdy’s tubercle
• End: 5 cm distal to the joint line

Internervous Plane

• Iliotibial band
• Biceps femoris

Superficial Dissection

• Mobilise skin flaps
• Identify & develop the plane between
  • Iliotibial band
    • Attaches to Gerdy’s tubercle
  • Biceps femoris
    • Head of fibula
• Incise the fascia between them being careful of
  • Common peroneal nerve
    • Posterior border of biceps tendon
• Exposes superficial lateral ligament

Deep Dissection

• Enter the joint either in front or behind the superficial lateral ligament
• Anterior arthrotomy
  • Lateral parapatellar approach
  • Begin 2cm above the joint line to avoid incising the meniscus
• Posterior arthrotomy
  • Identify
    • Lateral head of gastrocnemius
    • Lateral superior geniculate artery
      • Ligated
    • Popliteus tendon
    • Posterolateral corner
  • Longitudinal incision in capsule
    • Starting above the joint line to avoid cutting the meniscus or popliteus

Dangers

• Nerve
  • Common peroneal nerve
• Vessels
  • Lateral superior geniculate artery
    • Between lateral head of gastrocnemius & posterolateral capsule
• Popliteus tendon